1 // Copyright 2013 Google Inc. All Rights Reserved. 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 // 15 // This class models a sequence of literals and a backward reference copy. 16 17 #ifndef BROTLI_ENC_COMMAND_H_ 18 #define BROTLI_ENC_COMMAND_H_ 19 20 #include <stdint.h> 21 22 namespace brotli { 23 24 // Command holds a sequence of literals and a backward reference copy. 25 class Command { 26 public: 27 // distance_code_ is initialized to 17 because it refers to the distance 28 // code of a backward distance of 1, this way the last insert-only command 29 // won't use the last-distance short code, and accordingly distance_prefix_ is 30 // set to 16 Command()31 Command() : insert_length_(0), copy_length_(0), copy_length_code_(0), 32 copy_distance_(0), distance_code_(17), 33 distance_prefix_(16), command_prefix_(0), 34 distance_extra_bits_(0), distance_extra_bits_value_(0) {} 35 36 uint32_t insert_length_; 37 uint32_t copy_length_; 38 uint32_t copy_length_code_; 39 uint32_t copy_distance_; 40 // Values <= 16 are short codes, values > 16 are distances shifted by 16. 41 uint32_t distance_code_; 42 uint16_t distance_prefix_; 43 uint16_t command_prefix_; 44 int distance_extra_bits_; 45 uint32_t distance_extra_bits_value_; 46 }; 47 48 } // namespace brotli 49 50 #endif // BROTLI_ENC_COMMAND_H_ 51